Controlling alternating-current motors.



PATENTED JUNE 5, 1906.

' F. E. CASE. CONTROLLING ALTERNATING CURRENT MOTORS.

APPLICATION FILED JAN. 25. 1904.

WiCnesses.

'invm fon Frank ECase. am.

PATENTED JUNE 5, 1906.-

= F. E. CASE.

- CONTROLLING ALTERNATING CURRENT MOTQESI.

APPLICATION FILED JAN.25. 1904.

2 sums-sum z.

lnven-Lffn? FrankECwe.

Umrrnn STATES PATENT orrron FRANKE. CASE, OF SCHENECTADY,

, ELECTRIC COMPANY,- A CO To all whom, iv may concern: a

Be it known that I, FRANK E. CASE, a citizen of the Unite tady, in the cou ty of Schenectady and State of New York, have invented certain new and useful Improvements in Control-ling Alter nating-Current Motors, of which the following is aspecification.

My invention relates to control systems for alternating-current motors;-and its principal object is to provide a system especially adapted'for the operation of a car or train of cars driven by alternating-current motors,

although my invention is not limited to this particular application. a inventlomis applicable to any. system 'whe're aplurallty oraitemating-eurrent mo 5O two-or more motors their regulating transformers'or compensacordingly illustrate and of motors of the typ in hich currentis supplied to the field, while transformer,

tors must be simultaneously controlledgfrom one or more points. These are the-requirements in the control of a train of cars'dri-ven by motors on the several cars, and I shall ac.-

tion as applied to a train-control system.

The system of control which I em' loy depends u on the variation of speed an torque of an a ternating-current motor with variation of the impressed voltage; I have illus* trated my invention as applied to a plurality e known as repulsion, th rotor-winding is equipped with a commuta or and short-circmtin brushes. My in-. vention, however, is not limited to this type of motor, but is equallyapplicable toother types of alternating-cin'rent motors in which the speed and torque may be controlled by varying the voltageas 1813118 case, for instance, in the ordinaryseries motor adapted-- The vol-- for use with alternating currents. tage applied to a motor or to a group of motors may be varied conveniently by supplying the motor through a transformer or autothe latter being sometimes own as'a compensator, and byvarying the effective number of turnsto which the motor orgroup of motors is connected. By this means a considerable range of voltage impressed upon the motor may be obtained; but by my invention I greatly increase the range that may. be'obtained by combining orgroiips of motors with tors and varying the' connections of the compensators to the describe my invenf source of supply. By this NEW YORK, Assie'NoRTo RPORA TION OF'NEW YORK.

CONTROLLING ALTERNAT lliG-CURRENT MOTORS.

Specificatioh of Letters Patent. Application filed January 25,,1 9 04. Serial No. 190.425.

States, residing at Schenecf GENERAL Patented June 5, 1906.

means I am enabled .to obtain a much greater range ofyoltage and a more even and uniorm acceleration of the motors than has been obtained by other systems.

'Other features of my invention will appear from the following description and from the annexed drawings, in wh1ch I Figure 1 shows diagrammatically a system of control arranged in accordance with my invention, and Fig. 2 shows a series of diagrams illustrating some of the circuit arrangements claimed by mycontrolsystem In illustrating my invention I have showir two groups of motors M and M, each group containing three motors. The number of motors in each group, however, is of no importance, but may be varied to suit the particular conditions of each case. Each group of motors is shown connected, through its re 'versing-switch R or R, to an autotransformer or compensator A or A, which in turn is connected to a trolley or collecting-shoe T. I The motors, with their compensators and reversin'g-switches, comprise the work-circuit, which is shown in heavylines. Switches (1 b c,-!.&c.,' are arranged to connect the motors to different points on the compensator A,

' thusva'rying the voltage impressed upon the motors. The controlling-coils for switches a b c', &e., as well as the-controlling devices for the reversin switches R, are connected to the system 0 conductors 1 2 3, &c., to which is also connected a master-controller.

Itfwill be understood that the circuits for a. single car or locomotive are here shown and that the system of conductors 1 2-3, &c.,-

may be extended to. any length and that the controlling devices for any number of groups of motors, with their compensators, as well First, the.

is not necessary to 6, through the controlling-coil of switches a impressed voltage. As master-controller J is moved from position'2 to position 3 the only change that occurs is the opening of the circuit of the controlling-coilfor switches a and a and the'closing of the'circuits of the controlling-coils for switches b and bi. The point of connection of the motors is thus shifted along the compensator, so that the motors receive a higher impressed voltage. As master-controller J is moved on through its various d, &c., are in turn closed, until when switches f and f are closed the motors are connected trolling-coils for sw1tches-h and h The compensators are thus cut out of circuit',- d1

thereby avoiding any waste of current in the compensators," the master controllefr J is moved from position 7 to 8 thecircuits of the controlling-coils for switches s, f, and f are opened, allowing. these switches to'rfall.

Then as contact-finger k comes into engagei 'ment with its movable contact the circuit is closed from contact-finger [c to contact-finger k totrain-conductor 2, through the coils of switches g and p in parallel; toti'ain-conand to the secondary; of transformer ductor-5 .The two-compensators, are thus in parallel, as has been a contact, switches it and h :are closed, con

necting the twocompensators in parallel to: the source of current. When the position 9"? of the master'econtroller is reached, the cira and a are again closed and the two groups of motors are again connected totheir cuits-of the coils of switches In passing through the different positions ,to

14* the switches b c, &c., are operated inturn. The point, of connection of the motors is shifted along the compensator until at 14 q themotors are again connected across the terminals of the compensator directly to the line. At this position also contact-finger 7:"

leaves its movable contact and switches h and hare again opened, cutting the com- I pensators out of circuit.

. .pensators.

In Fig. 2.are shown diagrams corresponding to the positions of the maste'ncontroller 2 7 9 and 14 In position 2 the circuits at starting are compensatorsin seriesv and the motors connected across the first section of the com- In the diagram corresponding to r ositiggrufi ie'is ivith positionsto position-7 switches.

the specific form shown.

ea'dy described, and when contact-finger it" engages its second movable compensators.

.and a control system a shown with the two the motors aretehown connected 3 the compensatbrs cut out. In

compensators.- In the diagramcorresponding to position 14 the motors are shown con- .nected in parallel with the compensators cut out.

are indicated in the drawings as a b c, &c., may be of any welI-knownty'pe of switch suitable for the purpose. A number of such The electrically-controlled switches, which i switches are well known in the art, and I do 1 notconsider it necessary to ilhistrate a particular form, sincei any well-known type of electrically-controlledswitch suited for the purpose may be used.

Although I have illustrated acomplete control system, it is evident that it is not necessary that a controlsystem embodying my invention should contain all the elements illustrated and described or elements having For instance, a difl'erent form of alternating motor.may be used instead of the repulsion type as shown, a 'fierent form of reversing-switch ;may be used for the motors, and other parts of the system may be varied inform without departing from the spirit ofmy invention.

Other forms of voltageeregulating devices than the autotransformer or compensator here shown may be used, such as an ordinary regulating-transformer. It will be understood that when the .word compensator is in the appended claims it is not limited to the particular form shown, butis intended to include all forms of. regulating transformers. -Accordingly I do not -to' limit myself 'to the particular construction and arrangement of "parts here shown, since changes therein which do not depart from the spirit of my invention and which are the scope of the be obvious to those skilled in the art.

What I claim as new, and desire to secure "by Letters Patent of the United States,

1. In combination, a plurality ofalt'ernating-current motors, com devices adapted to vary t tion ofsaid motors to said for varying the relative connections of said compensators to each other, and means for controlling said devices from a distance.

2! In combination, a plurality of alternate ing-current motors, com ensatorsrthlerefor, apted .to vary the points of connection ofsaid motors to said ensators therefor, e pomtsof connecappended' claims willcompensators' and compensators and to the relative con nections'of. said compensators to each other.

3. In combination, apluralityof alternating-current motor-5,. compensators therefor,

and. a control -systemadapted to-connect said compensators in series i gnd to connect the motors to receive a fraction of the compensator voltage, then" to shift-Tthe connection of the motors to receive the wh le compensator volta e, then to connect the compensators in parallel and to connect the motors toreceive' a fraction of the compensator voltage, and then to shift the connections of the motors to receive the whole compensator voltage.

4. In combination, a plurality of alternating-current motors, compensators therefor, a control system comprising devices for varying the connections of said motors and cornpcnsators', and a master-controller adapted to control said devices and arranged to con- .nect said compensator-sin series and to connect the motors to part of the compensatorwindings, then to connect the motors across the whole compensator-windings, then to connect the compensators in parallel and to connect the motors to a part of the, compensatorwind-ings.

5. In combination, a plurality of alternating-current motors, coinpensators therefor, a control system comprising devices forvarying the co meiztions of said motors and compensators, and a masterscontroller adapted to control said devices end arranged to connect ssidicornpensators in series and to connect the motors to part of the compensatorwindings, then to connect the motors across the whole compensator windings, then to connect the compensators in parallel and to connect the motors toa part of the compensator-windings and to open the circuit of the .compensatorwmdings.

6. In combination, a plurality of alternating-current motors, compensators tlflGIEBfOi,x and a control systemadaptedtovarythe points of connection of said motors to said compensators and to vary therelative connections of said compensators and to open the circnitsof said compensators when said motors are connected across jthefi-terminals thereof i i i 7. In combination, a plurality of greups of I alternatii; r-curren-t motors, a source ntfcur the supply voltage,

rent-supply therefor, and a control system adapted to vary the sseriespa-rallel oonnec tions of said groups and to varyTthe voltage impressed upon eachgroup.- V I 8. In combination a plurality of alte rnating-current motors, ia source of current supply, and a controllingsystem-adapted,to connect said motors-in series andtoimpress upon said motors a fraction of thesupply voltage then to increase to the iull supply voltage the voltage impressed on said motors in series, then to connect said motors in parallel and to impress upon said motors a fraction of and then to increase to the full supply voltage the voltage impressed upon said motors in parallel.

'9, In combination, 'a plurality oi' alternating-current motors, compensators therefor,

' switches adapted to vary the points of con- .nection of said motors to said compensators,

switches adapted to vary the relative connections ofsaid' compensators to each other, and

. compensators s ceases a control system comprising devices adapted 129 \operate said switches.

10. In combination, a plurality of alternating-current motors, compensators therefor, switches adapted to vary the points of connection of said motors to said compensators, switches adapted to vary the relative connections of said compensator-s to each other, reversing-switches for said motors, and a control system comprising devices adapted to operate said switches. 11.111 combination, a plurality of alternating-current motors, compensators therefor, switches adapted to vary the points of connection of said motors to said compensators, switches adapted to vary the relative connections of said compensators to each other, reversing-switches for said motors, a control system. comprising devices adapted to operate said switches, a master controlswitch, and a switch controlling the devices for said reversing-switches. v

12. The method of controlling a plurality of alternating-current motors, which consists in connecting said motors to compensators,

varying the points of connection of the mo- 7 .connected in series to the source o current,

, shifting the connections of saidmQtors to said compensators to increase the voltage impressed upon said motors, then connecting said compensators in parallel to the source and then'again shifting the connections of said motors to ssid-compensators to increase the voltage impressed'on said motors. c

15. The method of controllingl a plurality of alternating-current motors, ich consists ,in-dividing said motors intogroup's, connecting the groups to the compensators connected in series to the sourgei'of current, shifting the' points of connectionlefsaid groups to said to increase the voltage impressed oii said groups, then connecting the compensators in parallel and again shifting the connections of said groups to the .com ensators to increase the voltage impresse said groups, I V i 16'. The method of controlling a plurality" of groups of alternating-current motors, whic consists in varying the series-parallel connections of said groups and varying independ ently the voltage impressedonzeach group.

17. The method of-centrellinga pls e' in connecting said motors in series and impressing on said motors a fraction of the sup- 7 hand this 22d day of January, 1904. 5 ply oltage the Voltageimpressed onsaid mo-"f ply Voltage, then increasing to the full suptors 1n series, then connecting said motors in parallel and impressing upon said motors a fraction of the supply voltage, and then i15- creasing to the full supply voltage the voltage impressed on said motors in parallel.

n Witness whereof I have hereunto set my FRANK E. "CASE. Witnesses:

BENJAMIN B. HULL, HELEN OREoRn; 

